Heating platen press

ABSTRACT

A heating platen press for manufacturing composition board, such as chipboard, shavings board, and the like. The press includes a stationary base unit and a movable press unit which respectively have working, heating platens directed toward each other and respectively provided with parallel working faces. These units are each composed of a box structure which includes, in addition to the heating platen, an opposed cover plate and longitudinal bracer bridges which extend between and engage the cover plate and heating platen. The heating platen and cover plate of each unit are formed with channels for conveying a temperaturecontrolling fluid therethrough, so that the entire unit can be heated and cooled. Each longitudinal bracer bridge has at least one row of such channels extending longitudinally through the bracer bridges.

O United States Patent [113,594,867

[72] Inventor Heinrich Pfeiffer 2,765,587 10/1956 Skerntt l. 18/17 PUXEppingen/Baden, Germany 3,241,189 3/1966 Siempelkamp v l. 100/93 P 312%?Primary Examiner-H. A. Kilby,.lr.

Altorney.r-Curt M. Avery, Arthur E. Wilfond, Herbert L. [45] Paenmd July1971 Lerner and Daniel J Tick [73] Assignee J. Diefienbacher G.m.b.l-{.

Maschinenfabrik Eppingen/Baden, Germany [32] Priority Oct. 28, 1967 [33]Germany [3x] I P 53 1854 ABSTRACT: A heating platen press formanufacturing composition board. such as chipboard, shavings board, andthe [54] HEATING PLATEN PRESS like, The press includes a stationary baseunit and a movable 27 Claims43 Drawing Figs. press unit whichrespectively have work ng, heatlrrg platens directed toward each otherand respectively provided with [52] U-S-Cl 18/17, arana] working faee5These units are each composed of a 100/93, 83/700, 269/3 box structurewhich includes, in addition to the heating platen, [5 I] ll!!- anoppesed cover plate and longitudinal bracer bridges which Fleld OfSearch 7 P, extend between and engage the cover plate and heating Hi83/699, 700; 100/93 295; 269/3131 platen. The heating platen and coverplate of each unit are 314 formed with channels for conveying atemperature-controlling [56] References Cited fluid therethrough, sothat the entire unit can be heated and cooled. Each longitudinal bracerbridge has at least one row of UNITED STATES PATENTS such channelsextending longitudinally through the bracer 269/313 bridges.

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1. In a heating plaTen press for manufacturing composition board, astationary base unit and a movable press unit respectively havingheating platens with respective parallel working faces opposite eachother, said units each being composed of a box structure including, inaddition to said heating platen, an opposed cover plate and longitudinalbracer bridges extending between and engaging said cover plate and saidheating platen, said heating platen and cover plate and saidlongitudinal bracer bridges of each unit being formed with channels forconveying a temperature-controlling fluid therethrough, so that theentire unit can be heated and cooled, at least one row of said channelsextending longitudinally through said bracer bridges.
 2. The combinationof claim 1, wherein at least two rows of said channels are situated inrespective planes parallel to and differently spaced from said workingface of said platen.
 3. The combination of claim 1 wherein both theheating platen and the cover plate of each unit are provided with atleast two rows of said channels situated in different respective planesparallel to said working face of each unit.
 4. The combination of claim3 wherein channels of said cover plate and bracer bridges together withsaid channels of said platen form at least one heating-fluid circuit,said circuit forming a heat reservoir of the entire mass of the boxstructure of each unit so that the heat of said reservoir is availablefor the press operations, and each platen forming a heating zone inwhich the channels thereof are connected into said circuit forcounterflow of the fluid so as to pass the stored heat from saidreservoir to said heating zone.
 5. The combination of claim 4 whereineach platen has the channels in the row nearest to said working facethereof forming a primary fluid-flow circuit, a secondary circuit means,the channels of the other row of each platen together with the channelsof said cover plate being parallel connected in said secondary circuitmeans, said channels of said bracer bridges forming two fluid-flow loopsparallel connected in said secondary circuit means.
 6. In thecombination of claim 5, each unit defining a neutral plane situatedmidway between and extending parallel to the platen and cover platethereof, said channels of said longitudinal bracer bridges beingsituated on both sides of said neutral plane, said row of channels ofsaid heating platen of each unit nearest to said working face thereofforming said primary circuit, said secondary circuit means comprising afirst and a second secondary circuit, said first secondary circuitincluding the other row of channels of said heating platen together withthe channels of said bracer bridges on the same side of said neutralplane as said heating platen, said second secondary circuit includingthe channels of said cover plate and the channels of said bracer bridgeson the same side of said neutral plane as said cover plate.
 7. Thecombination of claim 5 wherein the row of channels of said heatingplaten nearest to said working face thereof are connected in series withthe row of channels of said cover plate in said primary circuit, theother row of channels of said heating platen of each unit forming partof said secondary circuit means which has individual heating loopsincluding respective channels of said longitudinal bracer bridges. 8.The combination of claim 7 wherein the row of channels of the heatingplaten of each unit closest to said working face of said platen formspart of said primary circuit, the second row of each heating platentogether with said bracer bridge channels on the same side of saidneutral plane forming a first heating loop, said covering plate having asecond row of channels connected in parallel with said heating loop, asecond heating loop comprising the bracer bridge channels on the otherside of said neutral plane and forming therewith a first secondarycircuit, the other row of channels of said cover plate forming a secondsecondary circuit.
 9. In the combination of claim 1, each unit definingmidway between its heating platen and cover plate a neutral planeparallel to said heating platen and cover plate, said rows of channelsof said platen forming a primary circuit, said cover plate of each unithaving a pair of rows of channels which form a secondary circuit, saidlongitudinal bracer bridge channels being located above and belowrespectively said neutral plane, a secondary circuit having respectiveheating loops parallel connected with said bracer bridge channels aboveand below said plane respectively.
 10. In the combination of claim 3,each unit defining a neutral plane situated midway between and extendingparallel to the heating platen and cover plate thereof, saidlongitudinal bracer bridge channels being situated on both sides of saidneutral plane, the row of channels of said platen nearest to saidworking face thereof forming part of said primary circuit, a firstsecondary circuit, the other row of channels of said platen togetherwith the bridge channels on the same side of said neutral plane as saidplaten forming a heating loop of said first secondary circuit, a secondsecondary circuit, said cover plate of each unit having a row ofchannels connected with the channels of said bridges on the same side ofsaid neutral plane as said cover plate to form a heating loop of saidsecond secondary circuit.
 11. In the combination of claim 1, each unitdefining a neutral plane situated midway between and extending parallelto the heating platen and cover plate of each unit, said cover platehaving a pair of rows of said channels respectively situated in planeslocated at different distances from the working face of said platen,said bracer bridge channels being situated on both sides respectively ofsaid neutral plane, a primary circuit, the row of channels of saidplaten nearest said working face thereof together with one of the rowsof channels of said cover plate being connected in said primary circuit,a secondary circuit, the other rows of channels of said platen and coverplate being connected in said secondary circuit, and said bracer bridgechannels on opposite sides of said neutral plane being situated inrespective two heating loops which are parallel connected with saidsecondary circuit.
 12. The combination of claim 1 wherein the rows ofchannels of said platen form a pair of heating loops which start at sideedges of the platen and which alternately include channels of both rows.13. The combination of claim 1 wherein said interconnected rows ofchannels form a primary circuit, the cover plate of each unit also beingformed with a pair of rows of channels interconnected in the same way asthe channels of said platen of each unit and forming a secondarycircuit.
 14. The combination of claim 13 wherein said channels form apair of heating loops for supplying to at least one edge region of eachheating platen a greater amount of heat than to the remainder of theplaten.
 15. The combination of claim 1, wherein the channels of eachheating platen form a fluid circuit having outlets, and means responsiveto the temperature of the fluid at said outlets for controlling thetemperature of each unit.
 16. The combination of claim 1 wherein saidchannels form part of primary and secondary heating circuits, and saidprimary heating circuit having an amount of heat greater than that ofsaid secondary circuit by the extent to which heat is lost from theheating platen by radiation and withdrawal of heat to the material beingworked.
 17. The combination of claim 16 comprising means foradditionally heating the four corners of said heating platen forreducing heat losses at said corners.
 18. A heating platen press formanufacturing composition board, a stationary base unit and a movablepress unit respectively having heating platens with respectivelyparallel working faces opposite each other, each of said units beingcomposed of a plurality of box structures, each box structure inclUding,in addition to said heating platen, an opposed cover plate andlongitudinal bracer bridges extending between and engaging said coverplate and said heating platen, said heating plate and cover plate ofeach unit having at least two rows of channels fortemperature-controlling fluid, said channel rows being differentlyspaced from said working face, said plurality of box structures beingarranged in a row with all of said longitudinal bracer bridges parallelto each other and situated one after the other along said latter rowfrom one box structure to the next, a pair of cylinder-and-pistonassemblies coacting with each of said movable press units respectively,and a plurality of fastening means passing through said bracer bridgesand rigidly securing a plurality of said box structures together into anassembly forming one of said units.
 19. The combination of claim 18,comprising wedge means between and coactive with each pair of successivebox structures of each unit for adjusting the box structures so that theworking faces of the platens are in a common plane and for transmittingforces between the adjoining box structures.
 20. The combination ofclaim 18, comprising spacer plates of large area for determining thethickness of the work material, spacer members which carry said spacerplates and have the same area size as said plates, said spacer membersbeing situated beyond the pressing region of the platens, workingpistons operatively connected with each movable press unit fordisplacing the latter, and said spacer plates respectively having centerpoints situated in planes perpendicular to the axis of said piston. 21.The combination of claim 20 wherein one of said spacer members isprovided for each of said cylinder-and-piston units respectively and iscarried by the stationary box structures of the stationary base unit.22. The combination of claim 20 comprising a pair of tension columnsoperatively connected with each movable press unit, the surface area ofeach spacer plate and spacer member having a length corresponding to thedistance between said columns, said surface area being at least as greatas the area of the pressing surface of said working piston.
 23. Thecombination of claim 20 wherein pressure-distributing plates aresituated between and operatively connected with each movable andstationary unit for transmitting the pressure therebetween, saiddistributing plates respectively being situated along the axes of saidpistons which act on the movable unit whereby the pressure istransmitted through said pressure-distributing plates from said movableunit to said stationary unit, and said distributing plates carryingprotective plates situated in line with said spacer plates and spacermembers.
 24. The combination of claim 1 wherein the ratio between theheight of each of said longitudinal bracer bridges of a box structurewith respect to the width of the effective working face thereof issmaller than 1:1.8.
 25. The combination of claim 24 wherein each of saidlongitudinal bracer bridges is formed with an operating opening as wellas with thermal expansion openings, each box structure having a neutralplane extending parallel to and situated between said platen and coverplate thereof, and said thermal expansion openings being situated onboth sides of said neutral plane.
 26. The combination of claim 25wherein each box structure includes transverse ribs of rectangularconfiguration formed with cutouts at the four corners thereof and havingthermal expansion openings on both sides of said neutral plane.
 27. Thecombination of claim 26 wherein a press unit includes only a single boxstructure having more than four of said longitudinal bracer bridges andcorresponding transverse ribs and having walls operatively connectedwith more than two cylinder-and-piston assemblies for providing thepressing force.